This invention relates to a joint for rotatably connecting a vehicle suspension arm or other link mechanism.
Conventionally, in a joint a snap ring is attached to a groove formed in a mounting hole of a housing so as to prevent a bearing from coming out of the mounting hole in the housing. However, the gap interposed between the snap ring and the groove causes backlashes while the gap in the snap ring impairs the rigidity of the joint. Furthermore, the groove must be so narrow for holding the snap ring that the groove is difficult to form in the mounting hole of the housing, thus increasing the manufacturing costs.
To solve this problem Japanese Laid-open Patent Application No. S64-6512 proposes a joint comprising a plug engaged in a groove. The plug comprises an annular portion and a cylindrical portion. The end of the annular portion contacts the end of a bearing, and the cylindrical portion extends diametrically outward from the outer peripheral edge of the annular portion and stands along the axis of the housing. This prior art proposes another joint, in which the plug is first engaged in a stepped bore and the end of the cylindrical portion of the plug is then caulked, thus preventing the bearing from inadvertently disengaging from the mounting hole in the housing.
In this prior art the inner periphery of the housing still requires the groove for receiving the plug, and the problem is that such groove is difficult to form and manufacture. In another joint of the prior art, after the plug is engaged in the stepped bore, the end of the cylindrical portion is caulked, so that the bearing is securely held in the housing. If a galvanizing process or other surface treatment precedes the caulking process, the galvanized plate on the caulked portion would peel off, thus deteriorating the corrosion resistance of the joint. Therefore, the caulking process needs to precede the surface treatment. If the caulked portion of the plug is pressured to fit the joint onto the link mechanism, the caulked portion may not be able to resist the pressure directed thereto because of its thinness, thus decreasing the strength of the joint. The joint must be carefully assembled into the link mechanism so that the caulked portion of the plug can resist the pressure required for such assembling.